1. Field of the Invention
The present invention relates generally to electrical lighting devices and systems, and more particularly to a lighting device comprising a series of light emitting diodes (LEDs) incorporated within a clear or translucent tube or rod configured for installation in a conventional fluorescent light fixture. The present LED replacement light includes suitable light directing and/or diffusing means and compatible connector pins and electrical componentry as required for installation and operation in an existing fluorescent light circuit. Alternatively, the replacement may utilize conventional 110–115 volt alternating current or backup battery power as the electrical power source.
2. Description of the Related Art
A number of different principles of electrical lighting have been developed over the years. Incandescent lighting was the first lighting principle to receive widespread use, and is still the most widely used lighting principle used to date. More recently, the principle of electrically exciting a gas to produce light emission from the gas, has been used to produce usable light in the form of fluorescent lighting fixtures and the like.
Fluorescent lighting operates according to the principle of ionizing a gas contained within a sealed tube. The electrically excited gas produces light emission as it returns to its normal energy level. The light spectrum depends upon the type of gas within the tube, but conventional fluorescent lighting emits light in the ultraviolet spectrum, which is converted to visible light as it encounters the coating within the tube and causes the coating to fluoresce. Such fluorescent lighting also requires a relatively high voltage to produce the required ionization of the gas. This voltage may be provided by a starter which provides an inductive kick when current is shut off or reversed, the ballast serving to limit current in the arc between the filaments, or by high voltage windings loosely wound on the ballast itself in rapid start fluorescent lights.
As can be seen, the fluorescent lighting principle is relatively complex, but is the lighting means of choice in most businesses and the like due to the greater electrical efficiency provided. Nevertheless, repair can be costly in terms of both parts and labor, when ballasts and other components break down and require replacement. Also, the relatively high voltage required of such fluorescent lighting systems requires additional electrical insulation, and requires greater care to provide the degree of safety desired in such electrical devices.
Other principles of lighting have been developed more recently. Among these is the LED, or light emitting diode. Light emitting diodes (hereinafter referred to as “LEDs” throughout the present disclosure) operate generally as a conventional diode, i.e., allowing electrical current to pass through the device in one direction while blocking current flow in the opposite direction. LEDs provide another advantage during this operation, in that the passage of electrical current through the device also causes light to be emitted from the device. As development of such LEDs has progressed, different colors of light emission, light intensity, and other factors have also been developed.
LEDs provide many advantages in lighting, where they may be employed. LEDs are relatively cool in operation, and do not produce any significant amount of heat as a byproduct of their operation. Moreover, they are quite efficient in comparison to other types of lighting principles. LEDs are available in a number of different colors, and the lighting intensity may be varied by means of a simple variable resistor or rheostat, unlike fluorescent lighting. However, even with recently developed “super bright” LEDs, the light output of a single LED is relatively weak in comparison to a conventional fluorescent light unit. Nonetheless, an assembly of a series of LEDs in a single unit or fixture, can provide an equivalent amount of light to a fluorescent light fixture, at greatly reduced voltage requirements and reduced componentry.
Accordingly, the present invention provides a solution to the problem of relatively costly and fragile componentry used in fluorescent lighting, by providing “drop-in” replacement lighting units for fluorescent lighting tubes. The present replacement lighting units comprise various embodiments of cylindrical or tubular units, each containing a relatively large number of LEDs. The lighting units are equipped with support and contact pins which extend from each end of the units and secure in the conventional fluorescent light tube connectors found at opposite ends of every fluorescent light fixture. The present invention also includes the electrical componentry required to adapt the operation of an LED array to the electrical system of a fluorescent lighting fixture, with such electrical componentry being provided either internally within the replacement lighting unit or externally, as desired. The present system may bypass the ballast and starter components of the conventional fluorescent circuit, and may also make advantageous use of a rheostat to control the light and/or color output of the LED device, as desired.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is presented below.
U.S. Pat. No. 2,713,629 issued on Jul. 19, 1955 to Walter V. Etzkorn, titled “Luminous Bodies,” describes a series of embodiments of a relatively small diameter, flexible plastic tube which includes a number of relatively small glass fluorescent bulbs therein. The purpose of the Etzkorn light construction is to provide a lighting device which may serve in place of conventional neon tubes and the like, with the flexible plastic tube and relatively small, spaced apart light bulbs within the Etzkorn construction providing the flexibility required to allow the device to be bent and shaped as desired. This teaches away from the present lighting device, as the present light comprises various embodiments of a rigid, translucent tube or rod adapted for installation in a conventional fluorescent lighting fixture. An attempt to install the flexible lighting unit of Etzkorn in a conventional overhead fluorescent lighting fixture, would result in the Etzkorn fixture sagging of its own weight as it spanned the opposite fluorescent sockets of the fixture. Moreover, Etzkorn clearly does not anticipate such a use for his device, as he only describes its connection with a conventional household wiring circuit (col. 2, lines 45–46). As Etzkorn utilizes relatively high voltage components, i.e., fluorescent bulbs, he does not require means for reducing system voltage, as provided by the present invention. Also, it is noted that Etzkorn wires his fluorescent bulbs in parallel, so that the loss of a single bulb does not result in the entire display going out. In contrast, the present invention connects the individual LEDs in series. In this manner, each LED may act as a voltage reduction device for other LEDs in the circuit. As LEDs are extremely reliable, solid state devices, such a series circuit is still highly reliable in comparison with series circuits using devices operating by means of other principles.
U.S. Pat. No. 3,714,414 issued on Jan. 30, 1973 to Alf T. Sternius, titled “Ornamental Lighting Means,” describes a series of embodiments incorporating baseless miniature (incandescent) lamps or bulbs, arranged in series in a holding fixture of some sort. The problems with such incandescent units, i.e., heat, relatively short life, high current draw for the amount of light output, etc., are well known. Sternius only provides a conventional connector plug for electrically connecting his lighting apparatus to a conventional outlet. He clearly does not anticipate using his lighting device in a fluorescent light fixture, with its specially configured sockets, as he does not provide any means of stepping down the voltage of such a fluorescent fixture to that required for his incandescent lights.
U.S. Pat. No. 3,755,663 issued on Aug. 28, 1973 to Ben B. George, Jr., titled “Electrical Display Device And Method Of Making The Same,” describes various embodiments of a lighting device incorporating a number of small, baseless incandescent bulbs in a series-parallel circuit within a flexible plastic tube or sleeve. George, Jr. does not disclose any connector means configured for connecting to a conventional fluorescent light fixture, as provided by the present lighting system invention. The George, Jr. lighting system thus more closely resembles the system of the '629 U.S. patent to Etzkorn and certain embodiments of the '663 U.S. patent to Sternius, both discussed above, than it does the present invention.
U.S. Pat. No. 4,152,618 issued on May 1, 1979 to Osamu Abe et al., titled “Light-Emitting Display Device Including Light Diffusing Film,” describes an assembly including a relatively small light emitting element. The disclosure is not clear as to the principle of operation of the light emitting element, but it appears that an early light emitting diode device is described, at least very generally. However, Abe et al. are primarily concerned with various means for diffusing the light emitted from the light emitting device, rather than with any specific means for replacing an existing lighting device (e.g., a fluorescent tube) with a lighting device incorporating a number of light emitting diodes therein, as is the case with the present invention. Accordingly, no specific electrical connection means is disclosed by Abe et al.
U.S. Pat. No. 4,521,835 issued on Jun. 4, 1985 to Daniel H. Meggs et al., titled “Flexible Elongated Lighting System,” describes various embodiments of a lighting system employing a number of LED type lighting devices imbedded within a flexible plastic rod or the like. Meggs et al. describe a number of different internal shapes for the plastic rod, for transmitting or diffusing the light output of the LEDs. Meggs et al. are primarily concerned with emergency lighting systems, and include battery power for their lighting systems. However, they do not provide any means for replacing an existing fluorescent lighting unit with their LED light system, as opposed to the present invention which includes voltage reduction and compatible connection means for replacing a fluorescent tube with a unit of the present invention.
U.S. Pat. No. 4,581,687 issued on Apr. 8, 1986 to Hirobumi Nakanishi, titled “Lighting Means For Illuminative Or Decorative Purpose And Modular Lighting Tube Used Therefor,” describes a series of embodiments of tubular lighting elements employing numerous LED lights therein, in series array. However, Nakanishi states that his lighting elements are flexible, and thus they are not suited for installation across the span of a fluorescent light fixture, as provided by the present rigid lighting elements. Moreover, Nakanishi utilizes end connectors which are incompatible with the conventional sockets found in a fluorescent lighting fixture, and Nakanishi does not disclose any electrical apparatus for reducing the voltage from the higher voltage of a fluorescent fixture or even standard household alternating current, as provided by the present invention.
U.S. Pat. No. 4,665,470 issued on May 12, 1987 to Benjamin B. George, Jr., titled “Decorative Light Tubing And Method Of Manufacture Thereof,” describes the use of a transparent dielectric material which is poured into the light tube in a liquid state, to seal the lighting components therein. George, Jr. describes the bending of the electrical contact wires over the edges of the ends of the tube, to hold them in place. Such a configuration is not at all compatible with installation in a conventional fluorescent light fixture. George, Jr. does not anticipate such an installation for his lighting device, as he does not disclose any electrical componentry to adapt the relatively low power requirements of LED lighting to the high voltage of a fluorescent lighting system.
U.S. Pat. No. 4,901,207 issued on Feb. 13, 1990 to Naoki Sato et al., titled “Light Emission Element Array And Manufacturing Method Thereof,” describes a linear LED array having a converging lens with a cylindrical cross section installed thereover. The Sato et al. disclosure is directed primarily to means for roughening the external surface of the cylindrical lens in order to diffuse the light emanating therefrom, rather than dealing with any specific installation configuration for an LED array. Accordingly, Sato et al. do not disclose any form of physical connection means for their lighting apparatus, nor any electrical components for adapting an LED array to a fluorescent lighting fixture, as provided by the present invention.
U.S. Pat. No. 4,941,072 issued on Jul. 10, 1990 to Masami Yasumoto et al., titled “Linear Light Source,” describes a linear LED array and semicylindrical section lens therefor. As in the case of the '207 U.S. patent to Sato et al. discussed immediately above, Yasumoto et al. do not disclose any specific means for securing their lighting device in any form of fixture, fluorescent or otherwise, and do not disclose any form of electrical apparatus for adapting the relatively low voltage requirements of an LED circuit to the necessarily higher voltage of a fluorescent fixture or even conventional line current, as provided by the present LED replacement for fluorescent lighting invention.
U.S. Pat. No. 4,943,900 issued on Jul. 24, 1990 to Klaus Gartner, titled “Lighting Fixture,” describes a number of miniature incandescent bulbs electrically connected in series within a translucent tube. Gartner is directed particularly to end attachment means for his lighting tube, with each end connector comprising a male connector which fits into a female socket in the end of the tube. Each end of the Gartner tube contains only a single electrical conductor. The Gartner lighting device is thus incompatible with a fluorescent fixture, with its requirement for two parallel male electrical connector pins extending from each end of the lighting element, as provided by the present LED replacement device for fluorescent lighting.
U.S. Pat. No. 5,032,960 issued on Jul. 16, 1991 to Masaaki Katoh, titled “Light Source Device With Arrayed Light Emitting Elements And Manufacturing Therefor,” describes an LED lighting array comprising a linear group of LEDs installed beneath a semicylindrical converging lens. The Katoh configuration more closely resembles the lighting arrays of the Sato et al. '207 U.S. patent, and more particularly the Yasumoto et al. '072 U.S. patent, than it does the present invention. Katoh does not disclose any means for connecting his lighting array electrically or physically with a lighting fixture, and does not disclose any electrical apparatus for adapting his LED array for use in a conventional fluorescent lighting fixture, as provided by the present LED replacement lighting device.
U.S. Pat. No. 5,515,253 issued on May 7, 1996 to Fritz C. Sjobom, titled “L.E.D. Light Assembly,” describes a specific lens configuration for diffusing the light produced by an LED lighting array. Sjobom provides a plurality of LEDs on a circuit board, and overlays the assembly with his lens. The Sjobom LED lighting array is not installed within a hollow translucent tube nor disposed along a solid translucent rod, as is the case with the present LED lighting apparatus. Moreover, Sjobom does not disclose any form of end connectors for his lighting array, nor does he disclose any electrical apparatus for adapting an LED array for use with the higher voltage of a conventional fluorescent lighting system or 110–115 volt AC supply, as provided by the present LED replacement for fluorescent lighting invention.
U.S. Pat. No. 5,688,042 issued on Nov. 18, 1997 to Abolfazl Madadi et al., titled “LED Lamp,” describes an elongate bulb having an attachment base at only one end thereof. The lamp includes three elongate circuit boards, each having a series of LEDs installed thereon. The circuit boards are installed within the bulb to emit light in a general omnidirectional pattern. Madadi et al. do not provide any form of reflector or diffuser means with their light, as they intend it to be installed within a double faced, back lighted sign (e.g., exit signs, etc.). Moreover, as they intend their light to be used only in such relatively compact installations, they do not provide the conventional double parallel pin connectors at each end of the bulb, as is provided in the present LED replacement lighting.
U.S. Pat. No. 5,810,463 issued on Sep. 22, 1998 to Atsushi Kawahara et al., titled “Illumination Device,” describes an LED lighting device having either a row of LEDs which send their light through a generally cylindrical lens with reflectors thereon, or which may include an array of LEDs at one end of the lens. The lens of the Kawahara et al. lighting device includes a lateral extension, the end or edge of which is adjacent to the linear LED array. This shape is not compatible with installation within a conventional fluorescent light fixture, as provided by the present invention. Moreover, Kawahara does not disclose any electrical apparatus to provide compatibility with the relatively high voltages of a fluorescent lighting system or even conventional household supply current, as provided by the present invention.
U.S. Pat. No. 6,068,383 issued on May 30, 2000 to Roger Robertson et al., titled “Phosphorous Fluorescent Light Assembly Excited By Light Emitting Diodes,” describes a fluorescent lighting device which produces light in the visible spectrum by means of a fluorescent coating within the lighting apparatus, which in turn is excited by ultraviolet light produced by a number of LEDs within the device. The device of the Robertson et al. '383 U.S. patent is thus more closely related to a conventional fluorescent lighting assembly, than to the present invention. The only difference between the assembly of the Robertson et al. '383 U.S. patent and conventional fluorescent fixtures, is that conventional fluorescent lighting produces light in the ultraviolet spectrum by means of ionizing a gas within a tube, with the ultraviolet light produced by the ionized gas causing the fluorescent coating within the tube to fluoresce to produce light in the visible spectrum. The present invention does not produce any form of ultraviolet light; all light produced by the LEDs used in the present lighting apparatus, comprises light in the visible spectrum. There is no need to convert light from the ultraviolet spectrum to the visible spectrum, in the present lighting system invention. Moreover, the Robertson et al. '383 U.S. patent does not disclose any physical configuration for a lighting device which enables it to be installed within a conventional fluorescent lighting fixture, as provided by the present LED replacement for fluorescent lighting invention.
U.S. Pat. No. 6,139,174 issued on Oct. 31, 2000 to Mark M. Butterworth, titled “Light Source Assembly For Scanning Devices Utilizing Light Emitting Diodes,” describes a solid translucent rod which accepts blue light from an appropriate LED at one end thereof, and transmits the light outwardly through the side of the rod. A pair of fluorescent strips along the side of the rod produce light in different spectra, with a third strip passing the blue light therethrough. The Butterworth light apparatus is adapted for use in a scanning device, as are many of the lighting devices of the prior art discussed further above. Accordingly, no means of installing or operating the Butterworth apparatus in a conventional fluorescent lighting fixture, is disclosed.
U.S. Pat. No. 6,283,612 issued on Sep. 4, 2001 to Mark A. Hunter, titled “Light Emitting Diode Light Strip,” describes an elongate translucent tube with a plurality of LEDs installed in series therein. However, Hunter utilizes a separate power supply to step down the voltage from the conventional 110–220 volt supply to the reduced voltage required even for a series of LEDs. The Hunter power supply is a separate box, wired in series with the light by an elongate flexible cable and removable connector. Moreover, each end of the Hunter lamp includes a flexible cable extending therefrom, which is not compatible for installation in a conventional fluorescent light fixture. In addition, Hunter does not disclose any form of light reflecting or diffusing means for scattering the directional light of the LEDs in through a wide spread pattern, as provided by the present invention.
U.S. Pat. No. 6,331,915 issued on Dec. 18, 2001 to Kenneth J. Myers, titled “Lighting Element Including Light Emitting Diodes, Microprism sheet, Reflector, And Diffusing Agent,” describes sheet(s) of material having of a series of prismatic reflective grooves formed therein, and the placement of LEDs along the grooves. A number of additional means of diffusing or scattering the light emitted by the LEDs, is also described generally by Myers. However, the only electrical power source indicated in the Myers disclosure, is a conventional symbol for a battery across two of the LEDs in one of the drawing Figs. No description of this battery, its reference numeral, or any other electrical power means is provided in the text of the disclosure.
U.S. Pat. No. 6,388,393 issued on May 14, 2002 to Lewis Illingworth, titled “Ballasts For Operating Light Emitting Diodes In AC Circuits,” describes various embodiments of inductor and transformer devices for reducing voltage and current to proper levels, for powering LED lighting devices in an aircraft electrical system. Illingworth does not describe any type of connectors for connecting an LED light array in a fluorescent fixture, nor does he describe any means for reflecting or diffusing the light output from an LED array, which features are a part of the present invention. Moreover, Illingworth is directed to relatively low voltages, and particularly DC electrical power systems, as used in aircraft. Accordingly, he teaches away from the present invention, with its “drop-in” replacement in a fluorescent lighting fixture.
Finally, U.S. Patent Publication No. 2002/60,526 published on May 23, 2002 to Jos Timmermans et al., titled “Light Tube And Power Supply Circuit,” describes an elongate tube having a plurality of LEDs installed therein. Timmermans et al. also describe circuitry and connector means for installing their light in an existing fluorescent light fixture. However, Timmermans et al. vary the angles of their installed LEDs to provide the desired light projection. No light reflective or diffusion means is disclosed by Timmermans et al. in their light.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus an LED replacement for fluorescent lighting solving the aforementioned problems is desired.